Thermostatic circuit closer



- F. PAWLIK ET AL n THERMOSTATIC CIRCUIT CLOSER Fiied March 15. 1921vPatented Jan. 29, 1924.

UNITED STATES PATENT OFFICE.

FRANZ PAWLIK, F RORSCHACH, AND KARL ALTHEER, OF HORN, SWITZERLAND, AS-

SIGNORS TO JACOB SCHMIDHEINY, OF HIERBRUGG,

ST. GALLEN, SWITZERLANI THERMOSTATIC CIRCUIT CLOSER.

applicati@ med Maren 15,1921.

To all whom 'it may concern Be it known that we, FRANZ PAWLIK, a citizenof the Republic of Czechoslovakia, and a resident of Rorschach,Switzerland,

and KARL ALTHEER, a citizen of the Republic of Switzerland, and aresident of orn a. Bodensee, Switzerland, have invented certain new anduseful Improvements in Thermostatic Circuit Closers; and we do herebydeclare the following to be a clear,

fnll, and exact description of the invention,

such as will enable others skilled in the art to which it appertains tomake and use the same, reference being had to the accompanying drawingand to letters or figures of reference marked thereon, which form a partof this specification.

This invention relates to improvements in automatic temperature alarmdevices and consists essentially in an electric contact device,comprising a contact cartridge which can be repeatedly used after givingan alarm by simply turning it upside down. Automatic temperature alarmdevices are already known in which mercury or a fusible metal alloy isenclosed in a'metallic cartridge or casing and is normall supportedabove a contact pin by a solidified insulating mass,

which mass fuses upon an increase in temperature, whereby the mercury oralloy after the latter fuses is deprived of support and drops on thecontact pin, thus closing the alarm device. Such devices have thedisadvantage that a thin layer of the fusible insulating mass willremain on the metallic inner walls of the cartridge and will thusprevent makinlg a reliable contact.

A construction according to this invention is illustrated by way ofexample in the accompanying drawing in which:

Fig. l is an elevation of an apparatus enclosing the device;

Fig. 2 a view of the interior of apparatus, the protective casing beingin section;

Fig. 3 a longitudinal section of the contact cartridge,

Fig. 4 a cross-section on line A-B of Fig. 3,

Fig. 5 is a cross-section on line C-D of Fig. 6 illustrates alongitudinal section through a modified construction of a cartridge,

Fig. 7 is a cross-section along line E-F of Fig. 6 and Serial No.452,624.

Fig. 8 is a longitudinal section of the construction illustrated in Fig.5, the contact making parts being shown in a different operatingposition. n

According to F ig. 3, the contact cartridge comprises a thin met-al tube5 closed in an air-tight manner at both ends by means of insulatingplugs 3 and insulating cement masses 2. A contact pin l provided with acontact button and held in a central position, projects outwardly fromthe interior of the cartridge through each of the double plugs. Theremaining .inner space of the cartridge contains a solidified fusiblemass 7 and a solid metal conductor, as the lead cylinder 4 resting onthe latter; the said cylinder being centrally guided by means of threeContact springs 6 secured to its circumference and sliding on the innerwall of the metal tube.

The mass 7 is so selected that it will fuse on a given upper temperaturelimit being reached in the medium surrounding the cartridge. In this waythe lead cylinder is deprived of its solid support and owing to itsweight drops on the contact button of 'the pin 1, the liquid being atthe same time forced upwards.

As soon as the lead cylinder comes into contact with the contact button,the alarm circuit connected on the one hand to the metal tube and on theother hand to the but ton contact pin, will be closed, and an audible orvisible indication may be given at any desired point. After melting, themass will be situated above the lead cylinder. The cartridge cantherefore be used again immediately after the solidification of themelting` mass, by turning it u side down. For this reason it is easily.possible to test the apparatus at any moment, and it remains ready foruse for an unlimited time. In place of the lead cylinder 4 and of theinsulating mass 7 there may be used only a fusible mass constituted by ametal alloy which, on meltin'g, drops from a raised position andestablishes contact.

The modified cartridge illustrated in Figs. 6-8 shows only one contactpin l provided with a contact button 9 and held in a central position bymeans of a plug 3 of an insulatin cement mass by which the thin metaltue 5 is closed in an air-tight manner at one end, the other end of thetube 5 being closed by an integral ca A circular groove 8 is pressedinto the circumference of the tube 5 in order to retain the plug 3 inposition. Metallic contact balls l0 are provided between the cylinder land the button 9 or pin 1.

ln Fig. 6 the solidified fusible mass 7 supports the cylinder el and theballs l0. W hen the mass 7 fuses the cylinder and the balls drop, thelatter rest on the button 9 and the cylinder l rests on the balls (Fig.8). The balls are pressed towards the Wall ot the tube 5 by the actionof the conical ends of the cylinder Ll and ol the buttonV 9, whereby thealarm circuit, one ot the conductors of which is connected to the metaltube land the other to the Contact pin, is closed. ln korder to use thecartridge again, the latter is heated in the reversed position in Whichthe pin l points upwards, whereupon the mass 7 tuses and the cylinder' 4and the balls 10 drop tothe closed end olf tube v5. filter thesolidilication of the mass 7 the tube is turned upside down into theposition shown in Fig. 6 in which it may be used again.

Figs. 1,2 and 5 illustrate by VWay of eK- ample a construction eta'portable contact apparatus which may be connected to a Wall plug. To theYinsulating base c is secured in a depending position by means of aContact bracket CZ and clip o the above described Contact cartridge a.The metal tube ol the cartridge is in its turn electrically connected tothe binding screiv 1, Whilst the contact pin is connectcd'by means of acontact spring l and Wire m to the binding screw rll`he screws l and'forni a connection for the tufo conductors of `the cable c providedwith a plug at the end, Which can be inserted into the alarm circuit.lhe inner para ot the apparatus is protected by a casing or sleeveconstituted by two parts g and j' screwed together at it.

By using a contact cartridge, the apparatus may be secured to a ceilingor to a Wall, or any other'holding device.

l`he apparatus is speciallyv adapted for use as a lire alarm incombination With an electric alarm'deviee for notifying danger of lire,or ire after it has already broken out. Moreover the apparatus in asuitable form neaaoea may be used to give Warning when the higi estadmissible temperature reached in Warehouses of all kinds, and Wherethere is danger ot the temperature exceeding the limit in machine partsowing to heat genen ated by friction or on electric machine andapparatus etc.

is thedevice is comparatively inexpensive to manufacture it is possibleto equip the rooms 0r the materials to be protected. with a large numberoit' alarms in order to ensure the desired degree ol automaticsupervision.

llVe claim:

l. in electric contact device tor automatic temperature alarm devices,4in combination, a cartridge consisting of a metallic tube closed at oneend, a iusibe mass beingan electric insulator melting at a predeterminedtemperature and enclosed in said tube, a metal body and metal ballsarranged inside said tube and supported by said fusible mass anddeprived ot their support on the mass becoming fused. and an insulatedContact pin projecting through an air-tight closure provided at theother end of said tube into the interior oi the latter and eo-operatingwith said metal balls and body.

2. An electric Contact device lor automatic temperature alarm devices,in combination, a cartridge consisting or a metallic tube closed at itsupper end, a fusible mass being an electric insulator melting' atapredetermined temperature and enclosed in said tube, a metal bodyprovided With a conically shaped lower end and metal balls belovvfsaidmetal body, arranged inside said tube'and supported by said fusible massand deprived of their' support on the mass becoming fused, andaninsulated contact pin provided With a'conically'shaped button projectingthrough an air-tight closure provided at the lower end ot'said tube intothe interior of the latter and coo@L erating with said metal balls andbody.

ln testimony that We' claim the foregoing as our invention, We havesigned our names.

FRANZ Perl/VLH@ KARL ALTHEER.

